This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
In 1998, Cao Dai congregations that had grown up independently across the United States, Canada, Australia and France since 1975 gathered under the banner of a Caodai World Conference. Delegates voted to form the Caodai Overseas Missionary, an umbrella body uniting nineteen affiliated temples that had until then operated with no organizational connection to one another or to the bodies inside Vietnam.
The new body's charter was adopted at a convention held in Montreal, Canada, formally ratified by the general assembly on 6 September 1998. Congregations founded independently by refugees and emigrants after 1975 finally had a shared structure joining them together, more than two decades after the diaspora itself had begun.
The Caodai Overseas Missionary stated two objectives at its founding. It set out to propagate Cao Dai abroad, and to press for the pre-1975 Sacerdotal Council and its own Religious Constitution to be restored inside Vietnam, a position that placed it in ongoing tension with the government-recognised Cao Dai body Vietnam had established the previous year.
What the 1998 Montreal charter changed for Cao Dai's spread was giving nineteen separately founded diaspora temples across four countries a single overseas structure for the first time, one built explicitly in opposition to the Vietnamese state's own recognized organization rather than in cooperation with it.